Helicobacter pylori infection

Helicobacter pylori infection is also called H. pylori-related peptic ulcer disease. Most patients with persistent colonization are asymptomatic. Excluding medication-induced cases, >90% of patients with duodenal ulcers are colonized with H. pylori.

CASES/YEAR
90,000,000 (US); 6,000,000,000 (Global)
CATEGORY
AGENT TYPE
Bacteria
OTHER NAMES
H. pylori-related peptic ulcer disease;
ACUITY
Subacute/Chronic
INCUBATION
Unclear since infection usually occurs in childhood, and first recognized symptoms are in adulthood; GI symptoms reported 3-4 days after ingesting bacteria; [Public Health Agency of Canada: Pathogen Safety Data Sheet]
INITIAL SYMPTOMS
Most patients with persistent colonization are asymptomatic. Excluding medication-induced cases, >90% of patients with duodenal ulcers are colonized with H. pylori. As for non-ulcer dyspepsia, H. pylori is unlikely to cause >5-10%. [PPID, p. 2663]
PRECAUTIONS
Standard; [CDC 2007 Guideline for Isolation Precautions]
COMMENTS
EPIDEMIOLOGY:
After acquisition, usually in childhood, H. pylori infection persists for years or decades. High prevalence rates in conditions of poor sanitation, e.g., homes for mentally retarded and orphanages, suggest that fecal-oral transmission occurs. [PPID, p. 2661] Children probably acquire the infection from their parents or from other children. [Harrison ID, p. 523] Transmission is believed to be fecal-oral and possibly oral-oral. [CDC Travel, p. 215]

FINDINGS:
"Essentially all H. pylori-colonized persons have gastric tissue responses, but fewer than 15% develop associated illnesses such as peptic ulceration, gastric adenocarcinoma, or gastric lymphoma." [Harrison ID, p. 524]

LABORATORY DIAGNOSIS:
Screening of asymptomatic patients is not recommended. Use urea breath testing and stool antigen testing for initial diagnosis. Serological testing not recommended because of false positives. [Merck Manual, p. 118] Routine screening is not recommended. The stool antigen test (>90% sensitive & specific) is becoming the favored test for diagnosis. Serology cannot distinguish current from remote infection. "Whether to test and treat for H. pylori in patients with dyspepsia, GERD, pts taking NSAIDs, iron deficiency anemia or at risk for gastric cancer remains controversial." [ABX Guide] The 4 methods of testing are: 1.) Histologic exam of gastric mucosa biopsy (affected by sampling error); 2.) Serology (low predictive value in areas of low prevalence); 3.) Stool antigen test (more accurate than serology); and 4.) Urea breath test (becomes negative 4-6 weeks after effective antibiotic treatment); [Cecil, p. 875-6]
DIAGNOSTIC
Invasive (to exclude malignancy in older patients): biopsy urease test; Noninvasive (young dyspeptic patients): urea breath test; Use urea breath, stool antigen, or biopsy-based tests to determine the success of treatment; [Harrison ID, p. 525-6]
SCOPE
Global
SIGNS & SYMPTOMS
  • E dysphagia
  • G abdominal pain
  • G blood in stool
  • G hematemesis
  • G nausea, vomiting
  • H anemia
  • *cancer
  • *shock
  • *weight loss
ANTIMICROBIC

Yes

VACCINE

No

ENTRY
Ingestion
SOURCE
Person-to-Person, Human Fecal-Oral
RESERVOIR
Human
RISK FACTORS
TREATMENT
"Main treatment indication is PUD." [ABX Guide]
REFERENCES FOR CASES/YEAR
1. (US) Prevalence is about 30% (50% in those >60, 25% in 30-59 years old, and 5% in children. [Gorbach, p. 202]
2. (Global) H. pylori colonizes more that 1/2 of the world's population. Prevalence is about 80% in developing countries. [Gorbach, p. 202]